Cooking apparatus and control method thereof

ABSTRACT

A cooking apparatus has a cooking chamber, a microwave unit to radiate microwaves to the cooking chamber, a convection unit to supply hot air to the cooking chamber, a grill unit to supply radiant heat to the cooking chamber, an input unit to receive a cooking command and a control unit to perform a cooking corresponding to the received cooking command by performing one of a first heating stage and a second heating stage, and after performing the one of the first heating stage and the second heating stage, performing the other one of the first heating stage and the second heating stage. In the first heating stage, the control unit operates the microwave unit and at least one of the convection unit and the grill unit, and in the second heating stage, the control unit operates the grill unit and the convection unit while not operating the microwave unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.14/691,179, filed on Apr. 20, 2015, which is a Continuation of Ser. No.14/010,898, filed on Aug. 27, 2013, in the United States Patent andTrademark Office and claims the benefit of Korean Patent ApplicationNos. 10-2012-0095286, 10-2013-0008967 and 10-2013-0056086, filed on Aug.29, 2012, Jan. 26, 2013 and May 16, 2013, respectively, in the KoreanIntellectual Property Office, the disclosures of each of which areincorporated herein by reference.

BACKGROUND

1. Field

Embodiments of the present disclosure relate to a cooking apparatus andcontrol method thereof to achieve a fry-cooking process usingmicrowave-heating, convection-heating and grill-heating.

2. Description of the Related Art

A microwave oven is an appliance to cook food by supplying microwaves toa cooking chamber.

Recently-developed microwave ovens are equipped with a grill-heatingunit to generate radiant heat and/or a convection-heating unit togenerate convection heat in addition to a microwave-heating unit togenerate microwaves, to thereby cook food in various ways. Further,microwave ovens provide a function of automatically cooking food inaccordance with the kind of materials to be cooked by using variousheating sources. Microwave ovens provide functions of heating food usingmicrowaves, roasting food using a grill-heating unit, or cooking foodusing a convection-heating unit.

However, different from cooking methods of directly supplying thermalenergy to food, such as a roast-cooking method, a fry-cooking methodincludes processes of supplying thermal energy to oil and cooking foodthrough the heated oil. Thus frying is hard to realize using microwaveovens.

SUMMARY

It is an aspect of the present disclosure to provide a cooking apparatusand control method thereof to achieve a fry-cooking process usingfunctions of the cooking apparatus.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be obvious from the description, or may belearned by practice of the invention.

In accordance with one aspect, a control method of a cooking apparatusincluding a cooking chamber, a microwave-heating unit to radiatemicrowaves to the cooking chamber, a convection-heating unit to supplyhot air to the cooking chamber, and a grill-heating unit to supplyradiant heat to the cooking chamber, includes receiving a userfry-cooking command, performing a microwave-heating stage of activatingat least one of the convection-heating unit and the grill-heating unitand activating the microwave-heating unit, and performing a slim frystage of activating the grill-heating unit and the convection-heatingunit without activating the microwave-heating unit. Themicrowave-heating stage and the slim fry stage are performedcorresponding to the user fry-cooking command.

The performing the slim fry stage may include continuously activatingthe grill-heating unit and the convection-heating unit until atemperature of the cooking chamber reaches a preset target temperature,and intermittently activating the grill-heating unit and theconvection-heating unit after the temperature of the cooking chamberreaches the preset target temperature.

The intermittently activating the grill-heating unit and theconvection-heating unit may include repeating turn-on and turn-off ofthe grill-heating unit and the convection-heating unit.

The performing the microwave-heating stage may include activating theconvection-heating unit and the microwave-heating unit.

The performing the microwave-heating stage may include activating thegrill-heating unit and the microwave-heating unit.

The receiving the user fry-cooking command may include receiving inputsof user selections about the kind of materials to be cooked and a weightthereof.

The activating the microwave-heating unit may include deciding an outputpower of the microwave-heating unit in accordance with the kind of thematerials to be cooked and the weight thereof, and activating themicrowave-heating unit with the decided output power.

The activating the convection-heating unit may include deciding thetemperature of the cooking chamber in accordance with the kind of thematerials to be cooked and the weight thereof, and activating theconvection-heating unit in order to hold the temperature of the cookingchamber at the decided temperature.

If the microwave-heating stage is performed by activating theconvection-heating unit and the microwave-heating unit, a time of theslim fry stage may be longer than a time of the microwave-heating stage.

If the microwave-heating stage is performed by activating thegrill-heating unit and the microwave-heating unit, a time of themicrowave-heating stage may be longer than a time of the slim fry stage.

The user fry-cooking command may be input through a unitary buttonprovided at a control panel of the cooking apparatus.

In accordance with one aspect, a cooking apparatus includes a cookingchamber, a microwave-heating unit to radiate microwaves to the cookingchamber, a convection-heating unit to supply hot air to the cookingchamber, a grill-heating unit to supply radiant heat to the cookingchamber, a crusty plate configured to be heated by the microwaves, aninput unit to receive a user fry-cooking command, and a control unit.When the user fry-cooking command is input, the control unit performs amicrowave-heating stage of activating at least one of theconvection-heating unit and the grill-heating unit and activating themicrowave-heating unit, and performs a slim fry stage of activating thegrill-heating unit and the convection-heating unit without activatingthe microwave-heating unit.

The cooking apparatus may further include a temperature detecting partto detect an internal temperature of the cooking chamber. In the slimfry stage, the control unit may continuously activate the grill-heatingunit and the convection-heating unit until the internal temperature ofthe cooking chamber detected by the temperature detecting part reaches apreset target temperature, and may intermittently activate thegrill-heating unit and the convection-heating unit when the internaltemperature of the cooking chamber reaches the preset targettemperature.

The control unit may turn on and off the grill-heating unit and theconvection-heating unit at the same time in order to intermittentlyactivate the grill-heating unit and the convection-heating unit.

The control unit may activate the convection-heating unit and themicrowave-heating unit in the microwave-heating stage.

The control unit may activate the grill-heating unit and themicrowave-heating unit in the microwave-heating stage.

The crusty plate may include a metal plate having high heatconductivity, and a heating element to heat the metal plate by beingheated by the microwaves.

The heating element may be made of a ferrite-rubber composite.

The cooking apparatus may further include a high rack, on whichmaterials to be cooked are placed when the microwave-heating stage isperformed by activating the grill-heating unit and the microwave-heatingunit.

The cooking apparatus may further include a low rack, on which materialsto be cooked are placed when the microwave-heating stage is performed byactivating the convection-heating unit and the microwave-heating unit.

In accordance with one aspect, a control method of a cooking apparatusincluding a cooking chamber, a microwave-heating unit to radiatemicrowaves to the cooking chamber, and a convection-heating unit tosupply hot air to the cooking chamber, includes receiving a userfry-cooking command, performing a microwave-heating stage of activatingthe microwave-heating unit, and performing a slim fry stage ofactivating the convection-heating unit without activating themicrowave-heating unit. The microwave-heating stage and the slim frystage are performed corresponding to the user fry-cooking command.

The performing the slim fry stage may include continuously activatingthe convection-heating unit until a temperature of the cooking chamberreaches a preset target temperature, and intermittently activating theconvection-heating unit after the temperature of the cooking chamberreaches the preset target temperature.

A time of the slim fry stage may be longer than a time of themicrowave-heating stage.

The user fry-cooking command may be input through a unitary buttonprovided at a control panel of the cooking apparatus.

As described above, the cooking apparatus and control method thereofachieve the fry-cooking process using the microwaves, radiant heat andconvection heat without dipping the materials to be cooked in oil.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings of which:

FIG. 1 a is a view showing an exterior appearance of a cooking apparatusaccording to a embodiment;

FIGS. 1 b and 1 c are views showing additional accessories of thecooking apparatus according to the embodiment;

FIG. 2 is a view showing a control panel of the cooking apparatusaccording to the embodiment;

FIG. 3 is a view showing a microwave-heating unit and a grill-heatingunit of the cooking apparatus according to the embodiment;

FIG. 4 is a view showing a convection-heating unit of the cookingapparatus according to the embodiment;

FIG. 5 is a view showing internal airflow in a cooking chamber by theconvection-heating unit depicted in FIG. 4 ;

FIG. 6 a is a view showing an exterior appearance of a cooking apparatusaccording to a embodiment;

FIGS. 6 b and 6 c are views showing additional accessories of thecooking apparatus according to the embodiment;

FIG. 7 is a view showing a front appearance of the cooking apparatusaccording to the embodiment;

FIG. 8 is a view showing a control panel of the cooking apparatusaccording to the embodiment;

FIG. 9 is a view showing a microwave-heating unit and a grill-heatingunit of the cooking apparatus according to the embodiment;

FIG. 10 is a view showing a convection-heating unit of the cookingapparatus according to the embodiment;

FIG. 11 is a view showing internal airflow in a cooking chamber by theconvection-heating unit depicted in FIG. 10 ;

FIG. 12 is a control block diagram of the cooking apparatus according toan embodiments;

FIG. 13 is a flowchart showing a fry-cooking process of the cookingapparatus according to the embodiment;

FIGS. 14 and 15 are views showing an exemplary fry-cooking processcorresponding to the kind of food groups in the cooking apparatusaccording to the embodiment;

FIGS. 16 through 24 are views showing exemplary fry-cooking processcorresponding to the kind of materials to be cooked in the cookingapparatus according to the embodiment; and

FIG. 25 is a table abstracting the whole cooking methods depicted inFIGS. 16 through 24 .

DETAILED DESCRIPTION

Reference will now be made in detail to the embodiments, examples ofwhich are illustrated in the accompanying drawings, wherein likereference numerals refer to like elements throughout.

FIG. 1 a is a view showing an exterior appearance of a cooking apparatusaccording to a embodiment, and FIGS. 1 b and 1 c are views showingadditional accessories of the cooking apparatus according to theembodiment.

Referring to FIGS. 1 a through 1 c , the cooking apparatus 100 includesa main body 101 defining an exterior appearance, a cooking chamber 105provided inside the main body 101 to receive materials to be cookedtherein, a door 103 provided at a front portion of the main body 101 toopen and close an entrance of the cooking chamber 105, an electronicchamber 107 provided to the right of the cooking chamber 105, in which amicrowave-heating unit 120 is mounted, and a crusty plate 109 on whichmaterials to be cooked are placed.

A temperature sensor, which will be described later, to measure aninternal temperature of the cooking chamber 105 may be provided at aninner rear portion of the cooking chamber 105. A heat insulatingmaterial (not shown) is provided in a space between the main body 101and the cooking chamber 105. The heat insulating material wraps thecooking chamber 105 to thermally insulate the cooking chamber 105 fromthe exterior thereof.

The door 103 swings on a hinge 103 a connecting a side portion of thedoor 103 and the main body 101. When the door 103 is closed, the door103 is fixed to the main body 101 by a latch 103 b provided at the otherside portion of the door 103, opposite to the hinge 103 a.

As shown in FIG. 1 , the door 103 may be swingably mounted to afront-left side of the main body 101 using the hinge 103 a so that auser may open the door 103 using one hand and conveniently put or takematerials to be cooked into/out of the cooking chamber 105 using theother hand. Alternatively, as shown in FIG. 6 , the door 103 may beswingably mounted to a front bottom of the main body 101 using the hinge103 a so that a user may safely put or take materials to be cookedinto/out of the cooking chamber 105 using both hands.

The crusty plate 109, on which materials to be cooked are placed, may bedemountably provided in the cooking chamber 105.

The crusty plate 109 may be configured as a heating element, such as aferrite-rubber composite, which is heated by microwaves radiated fromthe microwave-heating unit 120. The crusty plate 109 may further includea metal plate having high heat conductivity in order to transfer theheat generated from the heating element to materials to be cooked. Insuch a case that the heating element is configured as a ferrite-rubbercomposite, the ferrite-rubber composite may function as an electricinsulator and prevent spark generation at the metal plate caused by themicrowaves.

The crusty plate 109 is heated by the microwaves radiated from themicrowave-heating unit 120, thereby directly heating a bottom of thematerials to be cooked.

The cooking apparatus 100 may further include a turntable 104 to rotatematerials to be cooked in the cooking chamber 105, and a high rack 102 aand a low rack 102 b to simultaneously cook two or more materials.

FIG. 2 is a view showing a control panel of the cooking apparatusaccording to the embodiment.

As shown in FIG. 2 , the control panel 110 is positioned at thefront-right portion of the main body 101. The control panel 110 includesan input unit 111 to receive inputs of user selections, and a displayunit 113 to display the operation state of the cooking apparatus 100.

The input unit 111 is positioned at a lower portion of the control panel110, and receives inputs of various user selections of cooking start,cooking time, cancel and pause. The input unit 111 may be configured asa button type switch, a membrane type switch, a dial switch and thelike.

The input unit 111 may include a fried food button 111 a to receive acommand for fry-cooking, a defrost button 111 b to receive a command fordefrosting, function select buttons 111 c to choose one of the heatingprocesses of microwave-heating, grill-heating and convection-heating, anadjustment dial 111 d to input a cooking time or a weight of materialsto be cooked, a cancel button 111 e to receive a command for operationstop of the cooking apparatus 100, and a selection/operation button 111f to receive a command for operation of the cooking apparatus 100.

The input unit 111, as shown in FIG. 2 , also includes printedcharacters explaining the function of each button 111 a through 111 f sothat a user may know the function of the corresponding button.

The display unit 113 is positioned at an upper portion of the controlpanel 110. The display unit 113 displays the operation state of theoutput of the cooking apparatus 100 and a cooking time. The display unit113 may be configured as a liquid crystal display (LCD) panel, a lightemitting diode (LED) panel or the like.

In the cooking apparatus 100 according to the embodiment, the input unit111 and the display unit 113 are segregated from each other; however,embodiments are not limited thereto. The input unit 111 and the displayunit 113 may be configured as an integrated touch screen panel (TSP).

FIG. 3 is a view showing a microwave-heating unit and a grill-heatingunit of the cooking apparatus according to the embodiment, FIG. 4 is aview showing a convection-heating unit of the cooking apparatusaccording to the embodiment, and FIG. 5 is a view showing internalairflow in the cooking chamber by the convection-heating unit depictedin FIG. 4 .

Referring to FIGS. 3 and 4 , the cooking apparatus 100 includes themicrowave-heating unit 120 to radiate microwaves into the cookingchamber 105, the grill-heating unit 130 to emit radiant heat towardmaterials to be cooked in the cooking chamber 105, and theconvection-heating unit 140 to supply hot air into the cooking chamber105.

The microwave-heating unit 120 is disposed in the electronic chamber 107provided to the right of the cooking chamber 105. The microwave-heatingunit 120 includes a magnetron 121 to generate microwaves which will beradiated into the cooking chamber 105, and a high voltage transformer(not shown) to apply high voltage to the magnetron 121.

The microwave-heating unit 120 radiates microwaves of 2.45 GHz into thecooking chamber 105 through the right wall plate of the cooking chamber105, thereby heating materials to be cooked in the cooking chamber 105.The microwaves radiated from the microwave-heating unit 120 maypenetrate materials to be cooked in the cooking chamber 105 and produceheat inside the materials to be cooked.

The microwave-heating unit 120 may be configured as a fixed outputmicrowave-heating unit which generates only the microwaves of maximumoutput power. The fixed output microwave-heating unit may radiatemicrowaves of various powers by adjusting a ratio of a microwaveradiation time to a non-radiation time. For example, in such a case thatthe maximum output is 900 W, the microwave-heating unit may radiatemicrowaves of an average of 600 W by repeating the radiation time of 20seconds and the non-radiation time of 10 seconds. However, embodimentsare not limited thereto. The microwave-heating unit 120 may also beconfigured as a variable output microwave-heating unit which radiatesmicrowaves of various powers by using an inverter as a driving circuit.

The grill-heating unit 130 is provided above the cooking chamber 105.The grill-heating unit 130 includes a grill heater 131 to emit radiantheat, and a reflection plate 133 to focus the emitted radiant heat onthe interior of the cooking chamber 105. The grill heater 131 may beconfigured as a halogen lamp which emits high radiant heat, or a heatingwire which emits heat by electric resistance.

The radiant heat emitted from the grill heater 131 is directly radiatedinto the cooking chamber 105, or is reflected from the reflection plate133 and then radiated into the cooking chamber 105, thereby heatingmaterials to be cooked in the cooking chamber 105.

The convection-heating unit 140 is provided to the left of the cookingchamber 105. The convection-heating unit 140 includes a convectionheater 141 to generate hot air, a convection circulation fan 143 tosupply the hot air around the convection heater 141 into the cookingchamber 105, and a convection driving motor 145 to rotate the convectioncirculation fan 143.

The left wall plate of the cooking chamber 105 has a depressed portion,which defines a circulation fan accommodation space 105 a. Theconvection heater 141 and the convection circulation fan 143 aredisposed inside the circulation fan accommodation space 105 a, and theconvection driving motor 145 is disposed outside the circulation fanaccommodation space 105 a.

By the rotation of the blades, the convection circulation fan 143 sucksthe internal air from the cooking chamber 105 into the circulation fanaccommodation space 105 a, and sends the air in a radial direction. Theconvection heater 141 is disposed around the outer circumstance of theconvection circulation fan 143, and heats the air blown from theconvection circulation fan 143. The convection heater 141 may beconfigured as a heating wire which emits Joule's heat by electricresistance.

A fan cover 147 is mounted between the circulation fan accommodationspace 105 a and the cooking chamber 105. The fan cover 147 functions toseparate the circulation fan accommodation space 105 a from the cookingchamber 105. A plurality of inlet holes 149 a are provided at thecentral portion of the fan cover 147. The internal air in the cookingchamber 105 flows into the circulation fan accommodation space 105 athrough the inlet holes 149 a. A plurality of outlet holes 149 b areprovided along the border portion of the fan cover 147. The hot air inthe circulation fan accommodation space 105 a flows into the cookingchamber 105 through the outlet holes 149 b.

The convection circulation fan 143 sucks the internal air from thecooking chamber 105 through the inlet holes 149 a, and sends the air ina radial direction. The convection heater 141 heats the air blown fromthe convection circulation fan 143. The hot air heated by the convectionheater 141 is supplied into the cooking chamber 105 through the outletholes 149 b.

Referring to FIG. 5 , the hot air heated by the convection heater 141 issupplied into the cooking chamber 105 by the convection circulation fan143, and then flows toward the right side surface of the cooking chamber105 along the top and bottom surfaces and the front and rear surfaces ofthe cooking chamber 105. After arriving at the right side surface of thecooking chamber 105, the hot air gathers at the middle portion of theright side surface, and then flows back toward the left side surfaceacross the middle portion of the cooking chamber 105. As describedabove, the hot air heated by the convection heater 141 circulates in thecooking chamber 105 by the convection circulation fan 143, therebyheating materials to be cooked in the cooking chamber 105.

FIG. 6 a is a view showing an exterior appearance of a cooking apparatusaccording to an embodiment, FIGS. 6 b and 6 c are views showingadditional accessories of the cooking apparatus according to theembodiment, and FIG. 7 is a view showing a front appearance of thecooking apparatus according to the embodiment.

As shown in FIGS. 6 a, 6 b and 7, the cooking apparatus 300 includes amain body 301 defining an exterior appearance, a cooking chamber 305provided inside the main body 301 to receive materials to be cookedtherein, a door 303 provided at a front portion of the main body 301 toopen and close an entrance of the cooking chamber 305, an electronicchamber 307 provided to the right of the cooking chamber 305, in which amicrowave-heating unit 320 is mounted, and a crusty plate 309 on whichmaterials to be cooked are placed.

Since the main body 301, the cooking chamber 305, the electronic chamber307 and the crusty plate 309 of the cooking apparatus 300 according tothe second embodiment of the present invention have the same functionsand structures as the main body 101, the cooking chamber 105, theelectronic chamber 107 and the crusty plate 109 of the cooking apparatus100 according to the first embodiment of the present invention describedabove with reference to FIG. 1 , explanation thereof will be omitted.

The door 303 swings on a hinge 303 a connecting a side portion of thedoor 303 and the main body 301. When the door 303 is closed, the door303 is fixed to the main body 301 by a latch 303 b provided at the otherside portion of the door 303, opposite to the hinge 303 a.

As shown in FIG. 6 a , the door 303 may be swingably mounted to a frontbottom of the main body 301 using the hinge 303 a so that a user maysafely put or take materials to be cooked into/out of the cookingchamber 305 using both hands. Alternatively, as shown in FIG. 1 , thedoor 303 may be swingably mounted to a front-left side of the main body301 using the hinge 303 a so that a user may open the door 303 using onehand and conveniently put or take materials to be cooked into/out of thecooking chamber 305 using the other hand.

The cooking apparatus 300 may further include a turntable 304 to rotatematerials to be cooked in the cooking chamber 305, and a high rack 302 aand a low rack 302 b to simultaneously cook two or more materials.

FIG. 8 is a view showing a control panel 310 of the cooking apparatusaccording to the embodiment.

As shown in FIG. 8 , the control panel 310 is positioned at thefront-right portion of the main body 301. The control panel 310 includesan input unit 311 to receive inputs of user selections, and a displayunit 313 to display the operation state of the cooking apparatus 300.

The input unit 311 includes a fried food button 311 a, a defrost button311 b, function select buttons 311 c, an adjustment dial 311 d, a cancelbutton 311 e, and a selection/operation button 311 f. The functions ofthe respective buttons 311 a through 311 f are the same as those of thebuttons 111 a through 111 f of the input unit 111 of the cookingapparatus 100 according to the first embodiment of the presentinvention.

The input unit 311, as shown in FIG. 7 , also includes printed symbolsrepresenting the function of each button 311 a through 311 f so that auser may know the function of the corresponding button.

Since the constitution and function of the display unit 313 are the sameas those of the display unit 113 of the cooking apparatus 100 accordingto the embodiment described above with reference to FIG. 2 , explanationthereof will be omitted.

FIG. 9 is a view showing a microwave-heating unit 320 and agrill-heating unit 330 of the cooking apparatus 300 according to theembodiment, FIG. 10 is a view showing a convection-heating unit 340 ofthe cooking apparatus 300 according to the embodiment, and FIG. 11 is aview showing internal airflow in the cooking chamber 305 by theconvection-heating unit 340 depicted in FIG. 10 .

Referring to FIGS. 9 and 10 , the cooking apparatus 300 includes themicrowave-heating unit 320 to radiate microwaves into the cookingchamber 305, the grill-heating unit 330 to emit radiant heat towardmaterials to be cooked in the cooking chamber 305, and theconvection-heating unit 340 to supply hot air into the cooking chamber305.

The microwave-heating unit 320 is disposed in the electronic chamber 307provided to the right of the cooking chamber 305. The microwave-heatingunit 320 includes a magnetron 321 and a high voltage transformer (notshown). The microwave-heating unit 320 radiates microwaves of 2.45 GHzinto the cooking chamber 305 through the right wall plate of the cookingchamber 305, thereby heating materials to be cooked in the cookingchamber 305.

The microwave-heating unit 320 may be configured as a fixed outputmicrowave-heating unit which generates only the microwaves of maximumoutput power, however embodiments of the present invention are notlimited thereto. The microwave-heating unit 320 may also be configuredas a variable output microwave-heating unit which radiates microwaves ofvarious powers.

The grill-heating unit 330 is provided at the inner surface of the topplate of the cooking chamber 305. The grill-heating unit 330 includes agrill heater 331 to emit radiant heat. The radiant heat emitted from thegrill heater 331 is directly radiated into the cooking chamber 305, oris reflected from the inner surface of the top plate of the cookingchamber 305 and then radiated toward materials to be cooked.

The convection-heating unit 340 is provided to the rear of the cookingchamber 305. The convection-heating unit 340 includes a convectionheater 341 to generate hot air, a convection circulation fan 343 tosupply the hot air around the convection heater 341 into the cookingchamber 305, and a convection driving motor 345 to rotate the convectioncirculation fan 343.

The rear wall plate of the cooking chamber 305 has a depressed portion,which defines a circulation fan accommodation space 305 a. Theconvection heater 341 and the convection circulation fan 343 aredisposed inside the circulation fan accommodation space 305 a, and theconvection driving motor 345 is disposed outside the circulation fanaccommodation space 305 a.

Since the convection heater 341, the convection circulation fan 343 andthe convection driving motor 345 are the same as those of the convectionheater 141, the convection circulation fan 143 and the convectiondriving motor 145 of the cooking apparatus 100 according to theembodiment, explanation thereof will be omitted.

Referring to FIG. 11 , the hot air heated by the convection heater 341is supplied into the cooking chamber 305 by the convection circulationfan 343, and then flows toward the front portion of the cooking chamber305 along the top and bottom surfaces and the left and right surfaces ofthe cooking chamber 305. After arriving at the door 303 provided to thefront of the cooking chamber 305, the hot air gathers at the middleportion of the door 303, and then flows back toward the rear surfaceacross the middle portion of the cooking chamber 305.

FIG. 12 is a control block diagram of the cooking apparatus according tothe embodiment.

In order to perform the cooking operation using the hot air, radiantheat or microwaves, the cooking apparatus 100 and 300 includes atemperature sensor 410, an input unit 111 and 311, a display unit 113and 313, a microwave-heating unit 120 and 320, a grill-heating unit 130and 330, a convection-heating unit 140 and 340, a control unit 420 and astorage unit 430.

Since the input unit 111 and 311, the display unit 113 and 313, themicrowave-heating unit 120 and 320, the grill-heating unit 130 and 330and the convection-heating unit 140 and 340 have been described above,explanation thereof will be omitted.

The temperature sensor 410 measures the internal temperature of thecooking chamber 105 and 305, and transmits the temperature data to thecontrol unit 410. The temperature sensor 410 may be configured as athermistor, which is a type of resistor whose resistance varies withtemperature.

According to the measurement result from the temperature sensor 410 andthe user operation command input through the input unit 111 and 311, thecontrol unit 420 controls the operation of the microwave-heating unit120 and 320, the grill-heating unit 130 and 330 and theconvection-heating unit 140 and 340.

The storage unit 430 stores the operation data corresponding to theabove-described fry cooking. The storage unit 430 responds to theoperation data request of the control unit 420, and transmits thecorresponding operation data to the control unit 420.

FIG. 13 is a flowchart showing a fry-cooking process of the cookingapparatus 100 and 300 according to the embodiment.

Referring to FIG. 13 , the cooking apparatus 100 and 300 determineswhether a user fry-cooking command is input through the fried foodbutton 111 a and 311 a at operation S210.

If the user fry-cooking command is input (Yes at operation S210), thecooking apparatus 100 and 300 displays the kind of fried food throughthe display unit 113 and 313 according to user selection using theadjustment dial 111 d and 311 d at operation S212. For example, if thefry-cooking command is input through the fried food button, the displayunit 113 and 313 displays the kind of fried food, such as potato chip,chicken nugget, frozen hotdog, sweet potato stick and the like.

The cooking apparatus 100 and 300 determines whether the user selectioncommand is input through the selection/operation button 111 f and 311 fwhile changing the kind of food displayed on the display unit 113 and313 at operation S214. In other words, a user may change the kind offood displayed on the display unit 113 and 313 using the adjustment dial111 d and 311 d. When the desired kind of food is displayed on thedisplay unit 113 and 313, the user may select the kind of food using theselection/operation button 111 f and 311 f.

If the user food selection command is input, the cooking apparatus 100and 300 displays the weight of food according to the user selectionthrough the adjustment dial 111 d and 311 d at operation S216.

The cooking apparatus 100 and 300 determines whether the user selectioncommand is input through the selection/operation button 111 f and 311 fwhile changing the weight of food displayed on the display unit 113 and313 at operation S218. In other words, a user may change the weight offood displayed on the display unit 113 and 313 using the adjustment dial111 d and 311 d. When the desired weight of food is displayed on thedisplay unit 113 and 313, the user may select the weight of food usingthe selection/operation button 111 f and 311 f.

If the weight of food is input, the cooking apparatus 100 and 300performs the fry-cooking operation according to the operation datacorresponding to the fried food mode, the kind of food and the weight offood selected by a user at operation S220.

Hereinafter, a method of heating the materials to be cooked of thecooking apparatus 100 and 300 according to the embodiment will bedescribed.

The cooking apparatus 100 and 300 may perform the microwave-heatingprocess, the grill-heating process, the convection-heating process, andthe slim fry or healthy fry heating process.

The microwave-heating process entails heating materials to be cookedusing the microwaves radiated from the microwave-heating unit 120 and320. In detail, if a user inputs the microwave-heating command throughthe input unit 111 and 311, the microwave-heating unit 120 and 320radiates the microwaves of previously determined power, e.g., 600 W,toward the materials to be cooked in the cooking chamber 105 and 305.

If the previously determined output of the microwaves is lower than themaximum output of the microwave-heating unit 120 and 320, themicrowave-heating unit 120 and 320 radiates the microwaves of thepreviously determined output by repeating turn-on and turn-off. In sucha case that the previously determined output of the microwaves is 600 Wand the maximum output of the microwave-heating unit 120 and 320 is 900W, the microwave-heating unit 120 and 320 is repeatedly turned on for 20seconds and turned off for 10 seconds to radiate the microwaves of 600W.

The grill-heating process entails heating materials to be cooked usingthe radiant heat emitted from the grill-heating unit 130 and 330. If auser inputs the grill-heating command through the input unit 111 and311, the grill-heating unit 130 and 330 emits the radiant heat towardthe materials to be cooked in the cooking chamber 105 and 305.

In detail, the grill-heating unit 130 and 330 is activated until thetemperature of the cooking chamber 105 and 305 reaches a preset targettemperature (e.g., 180° C.). If the temperature of the cooking chamber105 and 305 exceeds the preset temperature (e.g., 180° C.), thegrill-heating unit 130 and 330 is inactivated in order to preventoverheating. Afterward, if the temperature of the cooking chamber 105and 305 drops below the preset target temperature (e.g., 180° C.), thegrill-heating unit 130 and 330 is activated again.

The grill-heating process does not only heat the materials to be cooked,but also cooks the materials so that food may have a crispy texture andbrown color similar to food fried in oil.

The convection-heating process entails heating materials to be cookedusing the hot air supplied from the convection-heating unit 140 and 340.If a user inputs the convection-heating command, the convection-heatingunit 140 and 340 supplies the hot air into the cooking chamber 105 and305.

In detail, the convection-heating unit 140 and 340 is activated untilthe temperature of the cooking chamber 105 and 305 reaches a presettarget temperature (e.g., 200° C.). If the temperature of the cookingchamber 105 and 305 exceeds the target temperature, theconvection-heating unit 140 and 340 is inactivated. Afterward, if thetemperature of the cooking chamber 105 and 305 drops below the targettemperature, the convection-heating unit 140 and 340 is activated again.The temperature of the cooking chamber 105 and 305 is maintained at thetarget temperature in the above-described manner. In the case of anautomatic cooking process, the target temperature pre-stored in thestorage unit 430 may be used. In the case of a manual cooking process, auser may input the desired target temperature through the input unit 111and 311.

The convection-heating process does not only heat the materials to becooked, but also evaporates moisture of the surface of the materials tobe cooked so that the food may be crispy just like when food is fried.

The slim fry or healthy fry heating process, as an additional heatingprocess for fry-cooking, entails heating materials to be cooked usingthe radiant heat emitted from the grill-heating unit 130 and 330 and thehot air supplied from the convection-heating unit 140 and 340. That is,the convection-heating unit 140 and 340 is activated together with thegrill-heating unit 130 and 330, thereby performing the slim fry heatingprocess.

By activating the grill-heating unit 130 and 330 together with theconvection-heating unit 140 and 340, the cooking time may be shortened.Also, the food cooked by the grill-heating process may have a colorsimilar to that fried in oil. The side surface of the food cooked by theconvection-heating process is sufficiently heated, and moisture of thesurface of the food is evaporated. Accordingly, the food may have atexture similar to food fried in oil.

In detail, the materials to be cooked are heated by the radiant heatfrom the grill-heating unit 130 and 330 and the hot air from theconvection-heating unit 140 and 340 until the temperature of the cookingchamber 105 and 305 reaches a preset target temperature. So as tomaintain the target temperature of the cooking chamber 105 and 305, ifthe temperature of the cooking chamber 105 and 305 exceeds the targettemperature, the grill-heating unit 130 and 330 and theconvection-heating unit 140 and 340 are repeatedly turned on and off.

The grill-heating unit 130 and 330 and the convection-heating unit 140and 340 may be turned on and off at the same time. That is, if thetemperature of the cooking chamber 105 and 305 drops below the targettemperature, the grill-heating unit 130 and 330 and theconvection-heating unit 140 and 340 are turned on at the same time. Ifthe temperature of the cooking chamber 105 and 305 exceeds the targettemperature, the grill-heating unit 130 and 330 and theconvection-heating unit 140 and 340 are turned off at the same time.

Alternatively, if the temperature of the cooking chamber 105 and 305drops below the target temperature, the convection-heating unit 140 and340 may start operating. If the temperature of the cooking chamber 105and 305 exceeds the target temperature, the convection-heating unit 140and 340 may stop operating. During the operation of theconvection-heating unit 140 and 340, the grill-heating unit 130 and 330may be repeatedly turned on and off.

Alternatively, if the temperature of the cooking chamber 105 and 305drops below the target temperature, the convection-heating unit 140 and340 may start operating. If the temperature of the cooking chamber 105and 305 exceeds the target temperature, the convection-heating unit 140and 340 may stop operating. When the convection-heating unit 140 and 340starts operating, the grill-heating unit 130 and 330 may operatetogether with the convection-heating unit 140 and 340. When the presettime is over or the temperature of the cooking chamber 105 and 305reaches the target temperature, the grill-heating unit 130 and 330 maystop operating.

The fry-cooking process performed by the cooking apparatus 100 and 300according to the embodiment will be described hereinafter.

The cooking apparatus 100 and 300 may perform the fry-cooking process asone of the automatic cooking processes. The fry-cooking process mayinclude a microwave-heating stage to heat the core of the food and aslim fry stage to cook the food to have a texture and color similar tothat fried in oil.

In the microwave-heating stage, only the microwave-heating process maybe performed, the microwave-heating process and the convection-heatingprocess may be performed together, or the microwave-heating process andthe grill-heating process may be performed together. In detail, both thecore and surface of food are heated by activating only themicrowave-heating unit 120 and 320, activating both themicrowave-heating unit 120 and 320 and the convection-heating unit 140and 340, or activating both the microwave-heating unit 120 and 320 andthe grill-heating unit 130 and 330.

The core of food is heated by the microwaves from the microwave-heatingunit 120 and 320, and the surface of food is heated by the radiant heatfrom the grill-heating unit 130 and 330 or the hot air from theconvection-heating unit 140 and 340. Since the microwave-heating unit120 and 320 is activated together with the grill-heating unit 130 and330 or the convection-heating unit 140 and 340, the core as well as thesurface of food is sufficiently cooked, and the cooking time isshortened in comparison with the case of activating only thegrill-heating unit 130 and 330 or the convection-heating unit 140 and340.

Then, in the slim fry stage, the convection-heating process ofactivating the convection-heating unit 140 and 340 may be performed sothat the food may have a texture similar to that fried in oil, or theslim fry heating process of simultaneously activating the grill-heatingunit 130 and 330 and the convection-heating unit 140 and 340 may beperformed so that the food may have a color and texture similar to thatfried in oil.

The microwave-heating stage and the slim fry stage may be performed in arandom order. The slim fry stage may be first performed to make thesurface of the food crispy and the microwave-heating stage may besecondarily performed to heat the core of the food. Alternatively, themicrowave-heating stage may be first performed to heat the core of thefood and the slim fry stage may be secondarily performed to make thesurface of the food crispy. Further, the cooking apparatus 100 and 300may perform the fry-cooking process in order of the firstmicrowave-heating stage, the slim fry stage and the secondmicrowave-heating stage, or in order of the first slim fry stage, themicrowave-heating stage and the second slim fry stage. It may bepreferable that the slim fry stage is performed as the final stage ofthe fry-cooking process, because the crispy texture of the fried foodmay be maintained for a relatively long time.

Hereinafter, when a user inputs the fry-cooking command, the fry-cookingprocess of the cooking apparatus 100 and 300 according to the embodimentwill be described.

The materials to be cooked are classified into several food groups, andthe fry-cooking process of the cooking apparatus 100 and 300corresponding to each of the food groups will be explained.

A first food group is defined as primarily processed food. The primaryprocessing is the conversion of raw materials to food commodities, andthe first food group may include frozen hotdogs, frozen chicken nuggets,frozen potato chips, frozen croquettes, frozen spring rolls and thelike. A second food group is defined as non-processed food, and mayinclude drumsticks, raw potato chips, raw potato wedges, raw sweetpotato sticks and the like.

A first cooking time, a second cooking time and a third cooking time(which will be described later) may be different from each otheraccording to materials to be cooked and weights of the materials. Forexample, the first cooking time of the first food group and the firstcooking time of the second food group may be different from each other.

FIGS. 14 and 15 are views showing an exemplary fry-cooking processcorresponding to the kind of food groups in the cooking apparatus 100and 300 according to the embodiment.

If a user inputs the fry-cooking command through the fried food button111 a and 311 a, selects the material to be cooked and a weight of thematerial and inputs the operation command through theselection/operation button 111 f and 311 f, the cooking apparatus 100and 300 performs the operation which will be described below.

FIG. 14 shows an exemplary fry-cooking process with respect to the firstfood group in the cooking apparatus 100 and 300 according to theembodiment. Referring to FIG. 14 , the microwave-heating unit 120 and320 and the convection-heating unit 140 and 340 are activated at thesame time for the first cooking time, to thereby perform both themicrowave-heating process and the convection-heating process. When thefirst cooking time is over, the convection-heating unit 140 and 340remains activated, however, the activation of the microwave-heating unit120 and 320 is stopped, to thereby perform only the convection-heatingprocess until the second cooking time is over.

Particularly, the microwave-heating unit 120 and 320 is activatedtogether with the convection-heating unit 140 and 340 for the firstcooking time. As a result, the food may have a crispy texture by theconvection-heating, and also may be cooked to the core by themicrowave-heating.

Also, when the first cooking time is over, the activation of themicrowave-heating unit 120 and 320 is stopped, however, theconvection-heating unit 140 and 340 remains activated until the secondcooking time is over. As a result, the food may have a crispier texture.

Some kinds of materials may be cooked through only theconvection-heating process without heating the core of the food throughthe microwave-heating process. For example, the materials having arelatively small thickness, such as frozen potato chips, frozen Frenchfries or the like, may be sufficiently cooked to the core by theconvection-heating without the microwave-heating.

FIG. 15 shows an exemplary fry-cooking process with respect to thesecond food group in the cooking apparatus 100 and 300 according to theembodiments. Referring to FIG. 15 , the microwave-heating unit 120 and320 and the grill-heating unit 130 and 330 are activated at the sametime for the first cooking time, to thereby perform both themicrowave-heating process and the grill-heating process.

Because the primarily processed food already has a color similar to thatfried in oil through the primary processing, the primarily processedfood may be sufficiently cooked to have a texture similar to that friedin oil through only the convection-heating process. However, when thenon-processed food is cooked, the grill-heating process is performed forthe first cooking time so that the food may have a color and texturesimilar to that fried in oil and the microwave-heating process is alsoperformed for the first cooking time in order to heat the core of thenon-processed food.

When the first cooking time is over, the microwave-heating unit 120 and320 remains activated, however, the activation of the grill-heating unit130 and 330 is stopped. In addition, the convection-heating unit 140 and340 starts to be activated. Then, the microwave-heating unit 120 and 320and the convection-heating unit 140 and 340 are activated at the sametime until the second cooking time is over, to thereby perform both themicrowave-heating process and the convection-heating process. As aresult, the food may have a crispy texture while being heated to thecore.

When the second cooking time is over, the activation of themicrowave-heating unit 120 and 320 is stopped. However, theconvection-heating unit 140 and 340 remains activated to convection-heatthe food until the third cooking time is over. As a result, the food mayhave a crispier texture.

Hereinafter, the fry-cooking process of the cooking apparatus 100 and300 according to the embodiment will be explained by giving specificexamples of materials to be cooked.

FIGS. 16 through 24 are views showing exemplary fry-cooking processcorresponding to the kind of materials to be cooked in the cookingapparatus 100 and 300 according to the embodiment.

Referring to the fry-cooking process depicted in FIGS. 16 through 24 ,the whole fry-cooking process includes a first cooking stage, a secondcooking stage and a third cooking stage.

In the case of performing the fry-cooking process through the twocooking stages, the microwave-heating and grill-heating processes or themicrowave-heating and convection-heating processes are performed at thefirst cooking stage, in order to heat the core as well as the surface offood. Then, the slim fry heating process is performed at the secondcooking stage. As a result, the food may have a color, texture and tastesimilar to that fried in oil.

In the case of performing the fry-cooking process through the threecooking stages, the microwave-heating and grill-heating processes andthe microwave-heating and convection-heating processes are performed atthe first cooking stage and the second cooking stage, respectively, inorder to heat the core as well as the surface of food. Then, the slimfry heating process is performed at the third cooking stage. As aresult, the food may have a color, texture and taste similar to thatfried in oil.

In order that the food is evenly cooked, a user may be warned to turnthe food over at intervals between the respective cooking stages. Theoperation time of each cooking stage may be changed in accordance withthe kind of materials to be cooked and a weight of the material.

Numbers in bar graphs illustrated in FIGS. 16 through 24 represent theoutput of the microwave-heating unit 120 and 320 during themicrowave-heating process and the target temperature of the cookingchamber 105 and 305 during the convection-heating process. For example,“600 W” in the bar graph in FIG. 16 , which represents themicrowave-heating process during the first cooking stage, means that themicrowave-heating unit 120 and 320 operates with the power of 600 W.And, “200° C.” in the bar graph representing the convection-heatingprocess during the first cooking stage means that the temperature of thecooking chamber 105 and 305 is held at 200° C. by the convection-heatingprocess.

FIG. 16 is a view showing the fry-cooking process to fry-cook frozenpotato chips using the cooking apparatus 100 and 300 according to theembodiment.

In order that the frozen potato chips are evenly cooked, the turntable104 and 304 is placed in the cooking chamber 105 and 305, and the lowrack 102 b and 302 b is placed on the turntable 104 and 304. The crustyplate 109 and 309 is placed on the low rack 102 b and 302 b, and thefrozen potato chips are placed on the crusty plate 109 and 309.Accordingly, the bottom surfaces of the frozen potato chips are heatedby the crusty plate 109 and 309.

Referring to FIG. 16 , during the first cooking stage (e.g., whoseoperation time is 4 minutes for the frozen potato chips of 300 g to 350g, and 6 minutes for the frozen potato chips of 450 g to 500 g), boththe microwave-heating process and the convection-heating process areperformed in order to heat the core as well as the surface of the frozenpotato chips. For example, the microwave-heating unit 120 and 320 mayoperate with power of 600 W, and the convection-heating unit 140 and 340may operate to hold the temperature of the cooking chamber 105 and 305at the target temperature of 200° C.

As described above, the cooking apparatus 100 and 300 has a feature thatthe surface of the food is heated by the convection-heating process andthe core of the food is also heated by the microwave-heating process.Such a feature makes the cooking time shorter than that of theconvection-heating process.

When the first cooking stage is over, a user may be warned to turn overthe frozen potato chips in the cooking chamber 105 and 305 in order thatthe frozen potato chips are evenly cooked.

During the second cooking stage (e.g., whose operation time is 22minutes for the frozen potato chips of 300 g to 350 g, and 23 minutesfor the frozen potato chips of 450 g to 500 g), the slim fry heatingprocess is performed, in which the grill-heating unit 130 and 330 andthe convection-heating unit 140 and 340 operate at the same time. Forexample, the grill-heating unit 130 and 330 and the convection-heatingunit 140 and 340 may operate at the same time to maintain the targettemperature of 200° C. Since the temperature of the cooking chamber 105and 305 has already reached 200° C. by the convection-heating processperformed during the first cooking stage, the grill-heating unit 130 and330 and the convection-heating unit 140 and 340 are turned on and off atthe same time. As a result, the cooked potato chips may have a color,texture and taste similar to food fried in oil.

Due to the operation of performing the grill-heating process togetherwith the convection-heating process, the cooking time may be shortenedand the food may have a color similar to that fried in oil. In addition,due to the operation of performing the convection-heating processtogether with the grill-heating process, the overall surface of food mayhave a texture similar to food fried in oil.

FIG. 17 is a view showing the fry-cooking process to fry-cook frozenprawns using the cooking apparatus 100 and 300 according to theembodiment.

In order that the frozen prawns are evenly cooked, the turntable 104 and304 is placed in the cooking chamber 105 and 305, and the low rack 102 band 302 b is placed on the turntable 104 and 304. The crusty plate 109and 309 is placed on the low rack 102 b and 302 b, and the frozen prawnsare placed on the crusty plate 109 and 309. Accordingly, the bottomsurfaces of the frozen prawns are heated by the crusty plate 109 and309.

Referring to FIG. 17 , during the first cooking stage (e.g., whoseoperation time is 12 minutes for the frozen prawns of 200 g to 250 g,and 15 minutes for the frozen prawns of 300 g to 350 g), the slim fryheating process is performed, in which the grill-heating unit 130 and330 and the convection-heating unit 140 and 340 operate at the sametime. For example, the grill-heating unit 130 and 330 and theconvection-heating unit 140 and 340 may operate to maintain the targettemperature of 200° C. When fry-cooking the frozen prawns, because theprocess of heating the cooking chamber 105 and 305 in advance using theconvection-heating or grill-heating process is not performed, thegrill-heating unit 130 and 330 and the convection-heating unit 140 and340 are activated at the same time until the internal temperature of thecooking chamber 105 and 305 reaches the target temperature of 200° C.When the internal temperature of the cooking chamber 105 and 305 reachesthe target temperature of 200° C., the grill-heating unit 130 and 330and the convection-heating unit 140 and 340 are turned on and off at thesame time. As a result, the prawns cooked in the cooking apparatus 100and 300 may have a color, texture and taste similar to food fried inoil.

FIG. 18 is a view showing the fry-cooking process to fry-cook frozenchicken nuggets using the cooking apparatus 100 and 300 according to theembodiment.

In order that the frozen chicken nuggets are evenly cooked, theturntable 104 and 304 is placed in the cooking chamber 105 and 305, andthe low rack 102 b and 302 b is placed on the turntable 104 and 304. Thecrusty plate 109 and 309 is placed on the low rack 102 b and 302 b, andthe frozen chicken nuggets are placed on the crusty plate 109 and 309.Accordingly, the bottom surfaces of the frozen chicken nuggets areheated by the crusty plate 109 and 309.

Referring to FIG. 18 , during the first cooking stage (e.g., whoseoperation time is 5 minutes for the frozen chicken nuggets of 200 g to250 g, and 6 minutes for the frozen chicken nuggets of 350 g to 400 g),both the microwave-heating process and the convection-heating processare performed in order to heat the core as well as the surface of thefrozen chicken nuggets. For example, the microwave-heating unit 120 and320 may operate with power of 450 W, and the convection-heating unit 140and 340 may operate to maintain the target temperature of 200° C.

When the first cooking stage is over, a user may be warned to turn overthe frozen chicken nuggets in the cooking chamber 105 and 305 in orderthat the frozen chicken nuggets are evenly cooked.

During the second cooking stage (e.g., whose operation time is 2 minutesfor the frozen chicken nuggets of 200 g to 250 g, and 3 minutes for thefrozen chicken nuggets of 350 g to 400 g), both the microwave-heatingprocess and the convection-heating process are performed in order tosufficiently heat the core as well as the surface of the chickennuggets. For example, the microwave-heating unit 120 and 320 may operatewith power of 450 W, and the convection-heating unit 140 and 340 mayoperate to maintain the target temperature of 200° C.

During the third cooking stage (e.g., whose operation time is 5 minutesfor the frozen chicken nuggets of 200 g to 250 g, and 5 minutes for thefrozen chicken nuggets of 350 g to 400 g), the slim fry heating processis performed, in which the grill-heating unit 130 and 330 and theconvection-heating unit 140 and 340 operate at the same time. Forexample, the grill-heating unit 130 and 330 and the convection-heatingunit 140 and 340 may operate at the same time to maintain the targettemperature of 200° C. Since the temperature of the cooking chamber 105and 305 has already reached 200° C. by the convection-heating processperformed during the first and second cooking stages, the grill-heatingunit 130 and 330 and the convection-heating unit 140 and 340 are turnedon and off at the same time. As a result, the cooked chicken nuggets mayhave a color, texture and taste similar to food fried in oil.

FIG. 19 is a view showing the fry-cooking process to fry-cook frozenpotato croquettes using the cooking apparatus 100 and 300 according tothe embodiment.

In order that the frozen potato croquettes are evenly cooked, theturntable 104 and 304 is placed in the cooking chamber 105 and 305, andthe low rack 102 b and 302 b is placed on the turntable 104 and 304. Thecrusty plate 109 and 309 is placed on the low rack 102 b and 302 b, andthe frozen potato croquettes are placed on the crusty plate 109 and 309.Accordingly, the bottom surfaces of the frozen potato croquettes areheated by the crusty plate 109 and 309.

Referring to FIG. 19 , during the first cooking stage (e.g., whoseoperation time is 4 minutes for the frozen potato croquettes of 200 g to250 g, and 5 minutes for the frozen potato croquettes of 300 g to 350g), both the microwave-heating process and the convection-heatingprocess are performed in order to heat the core as well as the surfaceof the frozen potato croquettes. For example, the microwave-heating unit120 and 320 may operate with power of 600 W, and the convection-heatingunit 140 and 340 may operate to maintain the target temperature of 200°C.

During the second cooking stage (e.g., whose operation time is 12minutes for the frozen potato croquettes of 200 g to 250 g, and 14minutes for the frozen potato croquettes of 300 g to 350 g), the slimfry heating process is performed, in which the grill-heating unit 130and 330 and the convection-heating unit 140 and 340 operate at the sametime. For example, the grill-heating unit 130 and 330 and theconvection-heating unit 140 and 340 may operate at the same time tomaintain the target temperature of 200° C. Since the temperature of thecooking chamber 105 and 305 has already reached 200° C. by theconvection-heating process performed during the first cooking stage, thegrill-heating unit 130 and 330 and the convection-heating unit 140 and340 are turned on and off at the same time. As a result, the cookedpotato croquettes may have a color, texture and taste similar to foodfried in oil.

FIG. 20 is a view showing the fry-cooking process to fry-cook frozenspring rolls using the cooking apparatus 100 and 300 according to theembodiment.

In order that the frozen spring rolls are evenly cooked, the turntable104 and 304 is placed in the cooking chamber 105 and 305, and the lowrack 102 b and 302 b is placed on the turntable 104 and 304. The crustyplate 109 and 309 is placed on the low rack 102 b and 302 b, and thefrozen spring rolls are placed on the crusty plate 109 and 309.Accordingly, the bottom surfaces of the frozen spring rolls are heatedby the crusty plate 109 and 309.

Referring to FIG. 20 , during the first cooking stage (e.g., whoseoperation time is 3 minutes for the frozen spring rolls of 200 g to 250g, and 5 minutes for the frozen spring rolls of 350 g to 400 g), boththe microwave-heating process and the convection-heating process areperformed in order to heat the core as well as the surface of the frozenspring rolls. For example, the microwave-heating unit 120 and 320 mayoperate with power of 450 W, and the convection-heating unit 140 and 340may operate to maintain the target temperature of 200° C.

During the second cooking stage (e.g., whose operation time is 5 minutesfor the frozen spring rolls of 200 g to 250 g, and 7 minutes for thefrozen spring rolls of 350 g to 400 g), the slim fry heating process isperformed, in which the grill-heating unit 130 and 330 and theconvection-heating unit 140 and 340 operate at the same time. Forexample, the grill-heating unit 130 and 330 and the convection-heatingunit 140 and 340 may operate at the same time to maintain the targettemperature of 200° C. Since the temperature of the cooking chamber 105and 305 has already reached 200° C. by the convection-heating processperformed during the first cooking stage, the grill-heating unit 130 and330 and the convection-heating unit 140 and 340 are turned on and off atthe same time. As a result, the cooked spring rolls may have a color,texture and taste similar to food fried in oil.

FIG. 21 is a view showing the fry-cooking process to fry-cook homemadeFrench fries using the cooking apparatus 100 and 300 according to theembodiment.

In order that the homemade French fries are evenly cooked, the turntable104 and 304 is placed in the cooking chamber 105 and 305, and the lowrack 102 b and 302 b is placed on the turntable 104 and 304. The crustyplate 109 and 309 is placed on the low rack 102 b and 302 b, and thehomemade French fries are placed on the crusty plate 109 and 309.Accordingly, the bottom surfaces of the homemade French fries are heatedby the crusty plate 109 and 309.

Referring to FIG. 21 , during the first cooking stage (e.g., whoseoperation time is 8 minutes for the homemade French fries of 300 g to350 g, and 14 minutes for the homemade French fries of 450 g to 500 g),both the microwave-heating process and the convection-heating processare performed in order to heat the core as well as the surface of thehomemade French fries. For example, the microwave-heating unit 120 and320 may operate with power of 600 W, and the convection-heating unit 140and 340 may operate to maintain the target temperature of 200° C.

When the first cooking stage is over, a user may be warned to turn overthe homemade French fries in the cooking chamber 105 and 305 in orderthat the homemade French fries are evenly cooked.

During the second cooking stage (e.g., whose operation time is 18minutes for the homemade French fries of 300 g to 350 g, and 20 minutesfor the homemade French fries of 450 g to 500 g), the slim fry heatingprocess is performed, in which the grill-heating unit 130 and 330 andthe convection-heating unit 140 and 340 operate at the same time. Forexample, the grill-heating unit 130 and 330 and the convection-heatingunit 140 and 340 may operate at the same time to maintain the targettemperature of 200° C. Since the temperature of the cooking chamber 105and 305 has already reached 200° C. by the convection-heating processperformed during the first cooking stage, the grill-heating unit 130 and330 and the convection-heating unit 140 and 340 are turned on and off atthe same time. As a result, the cooked homemade French fries may have acolor, texture and taste similar to food fried in oil.

FIG. 22 is a view showing the fry-cooking process to fry-cook potatowedges using the cooking apparatus 100 and 300 according to theembodiment.

In order that the potato wedges are evenly cooked, the turntable 104 and304 is placed in the cooking chamber 105 and 305, and the high rack 102a and 302 a is placed on the turntable 104 and 304 so that the potatowedges may be sufficiently cooked by the radiant heat emitted from thegrill-heating unit 130 and 330. The crusty plate 109 and 309 is placedon the high rack 102 a and 302 a, and the potato wedges are placed onthe crusty plate 109 and 309. Accordingly, the bottom surfaces of thepotato wedges are heated by the crusty plate 109 and 309.

Referring to FIG. 22 , during the first cooking stage (e.g., whoseoperation time is 10 minutes for the potato wedges of 200 g to 250 g, 12minutes for the potato wedges of 300 g to 350 g, and 14 minutes for thepotato wedges of 400 g to 450 g), both the microwave-heating process andthe grill-heating process are performed in order to heat the core aswell as the surface of the potato wedges. Because the potato wedges arenot pre-processed food, it may be difficult to have a color similar tofood fried in oil through the convection-heating process. Accordingly,when cooking the potato wedges, the grill-heating process is performedtogether with the microwave-heating process during the first cookingstage. For example, the microwave-heating unit 120 and 320 and thegrill-heating unit 130 and 330 may operate with power of 300 W.

During the second cooking stage (e.g., whose operation time is 5 minutesfor the potato wedges of 200 g to 250 g, 5 minutes for the potato wedgesof 300 g to 350 g, and 5 minutes for the potato wedges of 400 g to 450g), the slim fry heating process is performed, in which thegrill-heating unit 130 and 330 and the convection-heating unit 140 and340 operate at the same time. For example, the grill-heating unit 130and 330 and the convection-heating unit 140 and 340 may operate at thesame time to maintain the target temperature of 200° C. Since thetemperature of the cooking chamber 105 and 305 has already reached 200°C. by the grill-heating process performed during the first cookingstage, the grill-heating unit 130 and 330 and the convection-heatingunit 140 and 340 are turned on and off at the same time. As a result,the cooked potato wedges may have a color, texture and taste similar tofood fried in oil.

FIG. 23 is a view showing the fry-cooking process to fry-cook drumsticksusing the cooking apparatus 100 and 300 according to the embodiment.

In order that the drumsticks are evenly cooked, the turntable 104 and304 is placed in the cooking chamber 105 and 305, and the high rack 102a and 302 a is placed on the turntable 104 and 304 so that thedrumsticks may be cooked by the radiant heat emitted from thegrill-heating unit 130 and 330. The drumsticks are placed on the highrack 102 a and 302 a to remove fat therefrom.

Referring to FIG. 23 , during the first cooking stage (e.g., whoseoperation time is 10 minutes for the drumsticks of 200 g to 250 g, 11minutes for the drumsticks of 300 g to 350 g, and 13 minutes for thedrumsticks of 400 g to 450 g), both the microwave-heating process andthe grill-heating process are performed in order to heat the core aswell as the surface of the drumsticks. Because the drumsticks are notpreviously-processed food, it may be difficult to have a color similarto food fried in oil through the convection-heating process.Accordingly, when cooking the drumsticks, the grill-heating process isperformed together with the microwave-heating process during the firstcooking stage. For example, the microwave-heating unit 120 and 320 andthe grill-heating unit 130 and 330 may operate with power of 300 W.

When the first cooking stage is over, a user may be warned to turn overthe drumsticks in the cooking chamber 105 and 305 in order that thedrumsticks are evenly cooked. Because the crusty plate 109 and 309 isnot used to remove fat from the drumsticks as described above, thebottom surfaces of the drumsticks may not be sufficiently heated.Therefore, a user may be recommended to pause the cooking process whilebeing warned to turn the drumsticks over.

During the second cooking stage (e.g., whose operation time is 7 minutesfor the drumsticks of 200 g to 250 g, 8 minutes for the drumsticks of300 g to 350 g, and 9 minutes for the drumsticks of 400 g to 450 g),both the microwave-heating process and the convection-heating processare performed in order to heat the core as well as the surface of thedrumsticks. For example, the microwave-heating unit 120 and 320 mayoperate with power of 300 W, and the convection-heating unit 140 and 340may operate to maintain the target temperature of 200° C.

During the third cooking stage (e.g., whose operation time is 7 minutesfor the drumsticks of 200 g to 250 g, 7 minutes for the drumsticks of300 g to 350 g, and 8 minutes for the drumsticks of 400 g to 450 g), theslim fry heating process is performed, in which the grill-heating unit130 and 330 and the convection-heating unit 140 and 340 operate at thesame time. For example, the grill-heating unit 130 and 330 and theconvection-heating unit 140 and 340 may operate at the same time tomaintain the target temperature of 200° C. Since the temperature of thecooking chamber 105 and 305 has already reached 200° C. by theconvection-heating and grill-heating processes performed during thefirst and second cooking stages, the grill-heating unit 130 and 330 andthe convection-heating unit 140 and 340 are turned on and off at thesame time. As a result, the cooked drumsticks may have a color, textureand taste similar to food fried in oil.

FIG. 24 is a view showing the fry-cooking process to fry-cook applehalves using the cooking apparatus 100 and 300 according to theembodiment.

In order that the apple halves are evenly cooked, the turntable 104 and304 is placed in the cooking chamber 105 and 305, and the low rack 102 band 302 b is placed on the turntable 104 and 304. The crusty plate 109and 309 is placed on the low rack 102 b and 302 b, and the apple halvesare placed on the crusty plate 109 and 309. Accordingly, the bottomsurfaces of the apple halves are heated by the crusty plate 109 and 309.

Referring to FIG. 24 , during the first cooking stage (e.g., whoseoperation time is 6 minutes for the apple halves of 300 g to 350 g, and9 minutes for the apple halves of 400 g to 450 g), both themicrowave-heating process and the grill-heating process are performed inorder to heat the core as well as the surface of the apple halves. Forexample, the microwave-heating unit 120 and 320 and the grill-heatingunit 130 and 330 may operate with power of 180 W.

During the second cooking stage (e.g., whose operation time is 4 minutesfor the apple halves of 300 g to 350 g, and 3 minutes for the applehalves of 400 g to 450 g), the slim fry heating process is performed, inwhich the grill-heating unit 130 and 330 and the convection-heating unit140 and 340 operate at the same time. For example, the grill-heatingunit 130 and 330 and the convection-heating unit 140 and 340 may operateat the same time to maintain the target temperature of 180° C. Since thetemperature of the cooking chamber 105 and 305 has already reached 180°C. by the grill-heating process performed during the first cookingstage, the grill-heating unit 130 and 330 and the convection-heatingunit 140 and 340 are turned on and off at the same time. As a result,the cooked apple halves may have a color, texture and taste similar tofood fried in oil.

FIG. 25 is a table abstracting the whole cooking methods depicted inFIGS. 16 through 24 .

Referring to FIG. 25 , the slim fry cooking mode includes the operationof performing the slim fry heating process during the last cookingstage, in which the convection-heating unit 140 and 340 and thegrill-heating unit 130 and 330 operate at the same time. Accordingly,the cooked food may have a color, texture and taste similar to foodfried in oil.

Although a few embodiments have been shown and described, it would beappreciated by those skilled in the art that changes may be made inthese embodiments without departing from the principles and spirit ofthe invention, the scope of which is defined in the claims and theirequivalents.

What is claimed is:
 1. A cooking apparatus comprising: a cookingchamber; a microwave heater configured to radiate microwaves to thecooking chamber; a heat convector including a convection heaterconfigured to generate hot air and a convection fan configured tocirculate the hot air to the cooking chamber; a grill heater configuredto generate radiant heat to the cooking chamber; a control panelconfigured to receive from a user a cooking command based on a userselection of a food to be cooked and a user selection of a weightthereof; and a controller electrically connected to the control panel,the microwave heater, the heat convector and the grill heater, andconfigured to control a cooking process for a duration of a firstheating stage and a second heating stage, wherein during the firstheating stage the controller is configured to control the microwaveheater so that the microwave heater radiates microwaves at apredetermined output power corresponding to the cooking command, and tocontrol one of the heat convector and the grill heater to repeat heatingand stopping heating to control an internal temperature of the cookingchamber corresponding to the cooking command while controlling anotherof the heat convector and the grill heater to stop the heating, duringthe second heating stage the controller is configured to control themicrowave heater so that the radiating of the microwaves stops, and tocontrol both the grill heater and the heat convector to repeat heatingand stopping, to control the internal temperature of the cooking chambercorresponding to the cooking command, the controller is furtherconfigured to sequentially perform the first heating stage and thesecond heating stage, in response to the cooking command and during thefirst heating stage the controller is configured to control themicrowave heater so that the microwave heater radiates microwaves at afirst predetermined output power according to a user selection of afirst food to be cooked and control the microwave heater so that themicrowave heater radiates microwaves at a second predetermined outputpower according to a user selection of a second food to be cooked, thefirst predetermined output power is different from the secondpredetermined output power, and the first food to be cooked is differentfrom the second food to be cooked.
 2. The cooking apparatus of claim 1,wherein, during the second heating stage, the controller is configuredto turn on the grill heater and the heat convector while controlling themicrowave heater so that the radiating of the microwaves stops, inresponse to the internal temperature of cooking chamber being below apreset target temperature.
 3. The cooking apparatus of claim 2, wherein,during the second heating stage, the controller is configured to turnoff the grill heater and the heat convector while controlling themicrowave heater so that the radiating of the microwaves stops, in orderto maintain the preset target temperature.
 4. The cooking apparatus ofclaim 1, wherein when the first heating stage is completed, thecontroller is configured to control the microwave heater so that theradiating of the microwaves stops.
 5. The cooking apparatus of claim 1,wherein when the first heating stage is completed, the controller isconfigured to maintain turning on the one of the heat convector and thegrill heater which is turned on in the first heating stage whilecontrolling the microwave heater so that the radiating of the microwavesstops.
 6. The cooking apparatus of claim 1, further comprising atemperature sensor connected to the controller to measure an internaltemperature of the cooking chamber, wherein, in the second heatingstage, the controller is configured continuously turn on the heatconvector and the grill heater until the internal temperature, measuredby the temperature sensor, of the cooking chamber reaches a presettarget temperature, and intermittently turn on and off the heatconvector and the grill heater after reaching the preset targettemperature in order to maintain the internal temperature of the cookingchamber at the preset target temperature.
 7. The cooking apparatus ofclaim 1, further comprising a temperature sensor connected to thecontroller to measure an internal temperature of the cooking chamber,wherein, in the second heating stage, when the controller is configuredto determine that the temperature, measured by the temperature sensor,of the cooking chamber is greater than a preset target temperature, thecontroller is configured to turn off at least one of the heat convectorand the grill heater in order to maintain the preset target temperature,and when the controller determines that the temperature, measured by thetemperature sensor, of the cooking chamber is less than the presettarget temperature, the controller is configured to turn back on the atleast one of the heat convector and the grill heater which is turned offin the second heating stage in order to maintain the preset targettemperature.
 8. The cooking apparatus of claim 1, further comprising atemperature sensor connected to the controller to measure an internaltemperature of the cooking chamber, wherein in the second heating stage,once the controller is configured to determine that the internaltemperature, measured by the temperature sensor, of the cooking chamberreaches a preset target temperature, the controller is configured torepeatedly turn on and off the at least one of the heat convector andthe grill heater during the second heating stage in order to maintainthe preset target temperature.
 9. The cooking apparatus of claim 1,wherein based on the substance and the weight of the substance input bythe user the controller determines a cooking time and a power level tobe used for the cooking.
 10. The cooking apparatus of claim 1, whereinthe controller is configured to perform the first heating stage for afirst time and perform the second heating stage for a second time, andthe first time is different than the second time.